Affinity of uterine luminal proteins for rat blastocysts

Tzartos, Socrates J.; Surani, M. Azim

doi:10.1530/jrf.0.0560579

Cited by 12 publications

(3 citation statements)

References 18 publications

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“…A similar increase in the high molecular weight proteins following administration of oestrogen to progesterone maintained ovariectomized rats has been recorded (Surani 1975). These high molecular weight proteins may regulate the metabolism of the embryo by binding to embryonic receptors (Surani 1977;Tzartos and Surani 1979). It is possible that some of these proteins could playa role similar to that of the specific protein isolated in the rabbit uterus called 'uterog10bin' (Beier 1968) or 'blastokinin' (Krishnan and Daniel 1967).…”

Section: Discussionmentioning

confidence: 71%

Influence of Environmental Factors on the Metabolism of Glucose by Preimplantation Mouse Embryos in vitro

Edirisinghe¹,

Wales²

1985

Aust. Jnl. Of Bio. Sci.

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The metabolism of glucose by late pre implantation mouse embryos was studied in a variety of media whose composition had been changed to reflect the environmental conditions in the uterus more closely than do standard culture media. The effects of combinations of energy substrates, the presence or absence of amino acids and the level of potassium in the medium were investigated.The use of energy substrates for in vitro culture at levels present in the uterine environment resulted in rates of synthesis and degradation of glycogen pools similar to those obtained using standard in vitro culture conditions but elevated incorporation into non-glycogen macromolecules. Amino acids influenced the metabolism of glucose by limiting the entry of glucose carbon into the non-glycogen macromolecular pool and directing more glucose into the synthesis of acid-soluble glycogen.Increasing the K + concentration to 60 mM in the culture medium caused a small but significant increase in the number of eight-cell embryos degenerating during culture for 24 h but the metabolism of glucose was unaffected over this time. At the time of morula transformation to the blastocyst this level of potassium ions suppressed glycogen synthesis by 50% over 5 h but did not affect its turnover during chase culture.It is concluded that factors other than those studied here contribute to the maintenance of the low glycogen levels found in uterine embryos. IntrodnctionEarlier work (Ozias and Stern 1973;Ozias and Weitlauf 1971;Snyder et al. 1971;Edirisinghe et al. 1984aEdirisinghe et al. , 1984b indicates that the uterine environment influences the metabolism of late preimplantation mouse embryos and in particular the utilization of glycogen stores. This environment is more complex than, and differs in the range and concentration of components from, the standard chemically defined media normally used for in vitro culture (Hamner 1971;Wales 1973;Beier 1974; Edirisinghe and Wales 1985). Changes in the environment may well be important in modifying the metabolism of glucose by embryos and be responsible for the differences in the turnover of glycogen in vivo as compared to its utilization in vitro.The possible control of glycogen metabolism by the level of exogenous energy substrate has been studied using different concentrations of the major energy substrates, glucose, lactate and pyruvate (Pike and Wales 1982). It is clear from this study that embryos, especially at the late preimplantation stages, have the ability to synthesize large amounts of glycogen and that the presence of the alternative energy substrates, lactate and pyruvate during culture influences the synthesis of glycogen, particularly when the medium contains a low concentration of glucose. Recently, the levels of lactate, pyruvate and glucose in the uterine fluid of mice have been measured and found 0004-9417/85/040411 $02.00

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Section: Discussionmentioning

confidence: 71%

Influence of Environmental Factors on the Metabolism of Glucose by Preimplantation Mouse Embryos in vitro

Edirisinghe¹,

Wales²

1985

Aust. Jnl. Of Bio. Sci.

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“…In rats and mice, stage-specific proteins have been isolated from uterine fluids immediately before implantation (Aitken, 1977;Tzartos & Surani, 1979) when there is, as observed in the pig, an alteration of the uterine environment. Embryos that are unable to respond to the altered uterine environment do not implant and are lost.…”

Section: Discussionmentioning

confidence: 99%

Development of pig blastocysts in a uterine environment advanced by exogenous oestrogen

Morgan¹,

Geisert²,

Zavy³

et al. 1987

Reproduction

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Routine embryo transfer techniques were used to establish recipient groups in which blastocysts were either asynchronous (blastocysts 24 h behind recipient uterus) or synchronous with their uterine environment. Oestradiol valerate (5 mg) was administered on Day 11 of the recipient's cycle to stimulate release of uterine secretion in the synchronous gilts (Group SE) and one group (AE) of asynchronous gilts. The gilts in the other asynchronous group (Group AC) were injected with vehicle (sesame oil). Embryos recovered on Day 14 by hysterectomy and flushing were evaluated for morphological development. Oestradiol treatment resulted in a failure of blastocyst development in Group AE gilts only. Recoverable oestradiol in the uterine flushings was increased in gilts in Groups AC and SE which contained elongated blastocysts. Plasmin inhibitor levels were lower in Groups AC and SE while PGF tended to be increased. Acid phosphatase activity was higher and recoverable Ca2+ was lower in Groups AE and SE. Failure of blastocyst development in Group AE is believed to have resulted from a failure to undergo trophoblastic elongation due to premature alteration of the uterine environment at a critical period of blastocyst development or from the presence of an unfavourable uterine environment for blastocyst attachment and development shortly after Day 12.

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“…The rise on Day 4, both quantitatively and quaUtatively, of uterine-secreted proteins makes it difficult to regard them as having a passive role, and the possible biological functions of these macromolecules requires investigation. Tzartos & Surani (1979) have used 125I-labelled uterine proteins to show that uterine proteins from Day 5 pregnant rats have a higher affinity for rat blastocysts than do uterine proteins from pro-oestrous animals or albumin. Such proteins may help to maintain optimal embryonic metabolism (Fishel & Surani, 1978).…”

Section: Discussionmentioning

confidence: 99%

Radiolabelled uterine proteins during early pregnancy and pseudopregnancy in mice after unilateral ovariectomy and superovulation

Fishel¹

1980

Reproduction

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Uterine secretions were analysed after labelling in vivo with L-[4,5-3H]leucine. The acid-precipitable counts were highest on Day 1 p.c., low on Day 2, lowest on Day 3, and similar to Day 2 values on Day 4 p.c. After unilateral ovariectomy the acid-precipitable counts for the horn ((+)ovary) ipsilateral to the remaining ovary were higher than those in the contralateral horn ((-)ovary) for each condition studied. Superovulation yielded slightly higher acid-precipitable counts in the (-)ovary and (+)ovary horns of pregnant mice on Day 3 p.c., and in the (+)ovary horn only for pseudopregnant mice on Day 2 p.c. The Day 2 counts for the (+)ovary and (-)ovary horns of the superovulating pseudopregnant mice were higher counts than those for superovulating pregnant mice, but the reverse occurred for (+)ovary horns only on Day 4 p.c. No qualitative differences between pseudopregnant and pregnant mice were observed on Day 4 and superovulation appeared to enhance the profiles obtained.

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Affinity of uterine luminal proteins for rat blastocysts

Cited by 12 publications

References 18 publications

Influence of Environmental Factors on the Metabolism of Glucose by Preimplantation Mouse Embryos in vitro

Influence of Environmental Factors on the Metabolism of Glucose by Preimplantation Mouse Embryos in vitro

Development of pig blastocysts in a uterine environment advanced by exogenous oestrogen

Radiolabelled uterine proteins during early pregnancy and pseudopregnancy in mice after unilateral ovariectomy and superovulation

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